This invention relates to the handling of the products of a plastic injection molding machine and more particularly to a system whereby the useful parts thereof may be separated from the scrap components thereof and for subsequently effecting a granulation of such scrap components. It is advantageous to granulate such scrap material in the vicinity of the injection molding machine so as to reduce manual handling of the material including such procedures as the temporary storage of the scrap next to the machine and thereafter its transportation to a central granulation point. The molds utilized in injection molding machines include those generally referred to as two-part molds and those generally referred to as three-part molds. In three-part injection molds, the sprue and runner assemblies are automatically discharged at a location remote from that at which the parts are discharged while in two-part molds, the sprue and runner assemblies although separate from the parts, are intermixed therwith. Recent improvements in equipment adapted for the handling, i.e. granulation of scrap material, in conjunction with three-part injection molds has been proposed. The present invention is, however, directed to the handling, i.e. parts separation and subsequent granulation of plastic scrap produced in association with plastic injection molding machines utilizing the above-described two-part mold system.
Objects of the present invention include a system and its operational manner which can be effective to separate injection molded parts from the scrap (sprues and runners) simultaneously formed therewith and thereafter accomplish the granulation of such scrap in an efficient, a low cost manner which is adapted for in situ use in conjunction with an injection molding machine.
These and other objects of the present invention are accomplished by a system for the separation of the injection molded plastic products including parts and sprue and runner assemblies formed simultaneously therewith wherein said parts are separate from but intermixed with said sprue and runner assemblies, said parts having a relatively small height dimension and said sprue and runner assemblies having a relatively large web-like, generally co-planar base portion and exhibiting at least one relatively large height dimension which is disposed generally normal to said base portion, comprising a supporting surface for receiving the molded products of a single injection molding cycle including said parts and said sprue and runner assembly therefor, means for conveying said products along said supporting surface, a first barrier disposed in spaced relation above said surface and movable between a first position spaced from said supporting surface at a distance greater than the relatively small height dimension of said parts and less than the relatively large height dimension of said sprue and runner assembly such that said parts are permitted to pass beneath the first barrier to the downstream side thereof while retaining said sprue and runner assembly on the upstream side thereof and a second position disposed at a height above said supporting surface greater than the relatively large height dimension of said sprue and runner assembly such that said assemblies may pass therebeneath to the downstream side thereof, a second barrier disposed downstream of said first barrier and movable between a first position wherein said second barrier forms a portion of said supporting surface and a second position elevated therefrom whereby products conveyed along said supporting surface upstream thereof will be deflected downwardly thereof, granulation means operatively associated with said second barrier and having at least a portion thereof disposed therebeneath, a parts receiving means disposed at the downstream terminus of said supporting surface and positioned therebeneath, and means responsive to each molding cycle of said injection molding machine for initially sequentially maintaining said first and second barriers in the first positions thereof such that parts from said molding machine on said supporting surface upstream of said first barrier will be conveyed initially beneath said first barrier and thereafter over said second barrier to said parts receiving means and thereafter for shifting the position of said first and second barriers to their second alternate positions whereby the sprue and runner assembly of said parts initially located upstream of said first barrier will passs therebeneath and be diverted by said second barrier into said granulation means thereby affecting a sequential separation of said parts and sprue and runner assemblies including the temporary storage of said parts and the granulation of said assemblies.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.